The U.S. Dietary Guidelines aim at provision of essential nutrients and preventive medicine measures of lowered saturated fat intake and inclusion of dietary fiber. Soluble fiber has been recognized as an influencing factor in control of serum cholesterol, a risk factor for cardiovascular disease. A balance between dietary fat from animal sources and cholesterol-modifying plant components is an ideal way to promote health, the cereal grain fiber offsetting a portion of dietary fat from animal products. This project has two phases; physiological and epidemiological. In the physiological, the mechanism of dietary fiber's effect on dietary fat will be examined by a series of animal experiments. The intestinal absorption of fat and cholesterol will be localized and measured, with varying levels of soluble fiber from barely grain. Barley is the highest known source of beta-glucan, the most viscous form of soluble fiber and viscosity in the intestine, is believed responsible for inhibition of fat absorption and consequent reduction of serum cholesterol. The objectives of these experiments will be to measure visocity of intestinal contents and the degree of fat and cholesterol absorption throughout. The small intestine and subsequent effects on blood cholesterol, in the presence of varying proportions of dietary soluble fiber. The intention is to determine a ration between dietary saturated fat, cholesterol and viscous soluble fiber for control of blood cholesterol. The second phase, epidemiological will survey a population sample of Montana Native Americans, for their dietary habits related to fat and fiber. The dietary risk factors will be correlated with serum cholesterol levels. This will provide the basis for follow-up nutrition education on Indian reservations, in collaboration with tribal health personnel.